1. Field of the Invention
This invention relates to a system for fastening a rail to a foundation to form a railroad track, and primarily to a fastening member in the form of a clip for securing the rail against extreme movements. This is important in maintaining the correct gage of the track despite variations in load on the rail. While there are many types of fastening systems utilizing clips for securing the rails, the present invention is of the type wherein one end of the clip is resiliently forced against the lower flange of the rail, and the other end rests upon a support which is spaced laterally of the rail. Intermediate of the rail and support is located an insert which is cast into and embedded in the foundation, which may be a tie or a sleeper; the insert extends above the surface of the foundation and is L-shaped so that crossbar of the insert is spaced above the foundation. The main body of the clip is placed under the crossbar so that the upper surface of the clip is held by the crossbar and permits the lower surface of the ends of the clip to maintain contact with the rail flange and the support.
2. Prior Art Statement
Fastening systems of the type generally described above are known and disclosed in the following publications:
Waters' U.S. Pat. No. 3,314,605 utilizes a clip made of a straight flat plate of spring steel. When the clip is installed and under stress as in FIG. 2, the clip is bowed slightly upwardly between the support 4 and the insert 5, and is bowed slightly downwardly between the insert and the flange-contacting end. An insulator 6 is placed over the flange and the end of the clip actually contacts the insulator, rather than the flange itself.
Waters' et al U.S. Pat. No. 3,515,347 has a similar arrangement to the earlier Waters' patent, but the insulator on the flange is specially shaped to receive the bifurcated ends of the clip. In addition, the support has a specially shaped depression to receive the other end of the clip.
Serafin et al utilizes a U-shaped steel clip which has outwardly extending legs that bear against an insulator on the rail flange to secure the rail in place. The other end of the clip forming the bight of the clip contacts the support member.
Gehrke is primarily directed to a pad placed under a rail, but also discloses a metal leaf spring which acts to secure the rail. It has a configuration generally similar to the clips of the Waters' patents.
Hixson also discloses a flat clip similar to Waters', also made of metal, and shaped so that the ends resting on the support fit within recesses on the support.
A BTREC advertisement of BTREC Inc. (date unknown) illustrates a clip which is similar to Waters', and is believed to be related to Waters'.